Jar-seal tester



E. B. BIRKENBEUEL.

JAR SEAL TESTER.

APPLICATION FILED MAR.20.,1919.

1,340,473. Patented May 18,1920.

INVENTOR fawmaflfimrmazm UNITED STATES PATE E- EDWARD B. BIBKENBEUEL, 0F PORTLAND, OREGON.

"JAB-SEAL TESTER.

To all whom it may concern:

Be it known that I, EDWARD B. BIRKEN- BEUEL, a citizen of the United States, and a resident of Portland, county of Multnomah, and State of Oregon, have invented a new and useful Jar-Seal Tester, of which the following is a specification.

My invention relates more particularly to that class of fruit jars having a more or less flexible cap, and to a means for testing the state of preservation of their contents.

The object of myinvention is to render it possible to determine the condition of the contents of a jar by simply moving the tester across the cap.

It is a commonly known fact that the caps are held on fruit jars by a reduction of the internal pressure through cooling, and that the pressure thus exerted on the cap causes it to be bent toward the inside of the jar, thereby presenting a concave face to the outside. The lower the pressure within the jar the greater will be the degree of curvature of the cap. To utilize this condition I have constructed my device as follows:

Referring to the drawing. Figure 1 is a plan of the device showing the manner of application; Fig. 2 is an elevation showing a with a poor seal and a flat cap; Fig. 3 is an elevation showing a perfectly sealed jar with the cap bent inward; Fig. 4% is a perspective view of my device with a portion cut away to show the scribing point.

Like letters and number of reference re fer to the same or similar parts throughout the several views.

Referring in detail to the drawing. J represents the ordinary glass fruit jar which is closed by the cap C the body or center of which I shall designate as C It will be noticed that the portion C is not backed up by a thickness of porcelain as is customary in some types of fruit jars, to which my device is not applicable.

The elements of my jar seal tester consists of a flat frame member T the ends of which are turned down to form the stops T' which have a distance between them somewhat greater than the outside diameter of the fruit jar cap. Midway between the stops T and extending in the same direction, is the sharpened scriber point S which has a tapered body S which fits into a corresponding hole in the bar T and it is riveted thereto at S.

Specification of Letters Patent.

The operation of mydeviceis as follows: After food has been placed in the jars for the purpose of preserving same, it is ordinarily a simple matter to detect jars with imperfect seals, but oftentimes, due to im' perfect sterilization, chemicalization takes place which will destroy the seal, and the contents of the jar .may be lost. Since the cap may adhere tightly to the jar in spite of an imperfect seal, the adhesion test is by no means reliable.

By placing my tester on a jar in question, as shown in Fig. 2, it will be seen that the "scriber point S rides on the cap body C and any movement of the tester with a slight downward pressure will mark the cap, thereby indicating a poor seal. If, however, the cap body C is depressed by the atmospheric pressure, the tester will ride on the outer edge of the cap but the scriber points will not touch anything.

The simplicity and-utility of my device are veryapparent, when it is considered tect by Letters Patent of the United States,

1. In a devicefor testing flexible metal jar caps, a body member of a relatively rigid material having a fiat bearing surface.

bounded'by a pair of integral downwardly extending ends and having at a point midway between said ends a marking scribe having a pointed tip extending below the bearing face of said bar. a

2. In a device for testing flexible metal jar caps, a body member having a downwardly extending portion at either end, said portions being spaced apart at a distance somewhat in excess of the diameter of the cap to be tested, and having a straight hearing surface for the top of the cap near each downwardly directed portion and having at a central point a scribe the point of which lies at a fixed distance below the bearing Patented May 18,1920.

- Application filed March 20, 1919. Serial No. 283,781.

surfaces and in the direction of said downwardly directed portions.

3. In a device for testing jar caps of flexible metal, a body of relatively rigid ma- 5 terial having a fiat lower bearing face and having its two ends extending downwardly to form stops at a greater distance apart than the diameter of said flexible metal jar cap, and a marker or scribe in fixed position on said .body approximately midway between saidends and extending a fixed distance below the lower bearing face of said body and in the direction of said clownwardly directed end portions.

EDWARD B. BIRKENBEUEL. 

